Positive Displacement Pumps

A Positive Displacement Pump has an expanding cavity on the suction side and a decreasing cavity on the discharge side. This tool provides calculators for speed corrections based on liquid viscosity and water temperature for both reciprocating and rotary pumps.

Reciprocating Pumps - Speed Correction vs. Viscosity

Speed reduction percentage based on liquid viscosity (SSU) for reciprocating pumps.

Liquid Viscosity (SSU)	Speed Reduction (%)
250	0
500	4
1000	11
2000	20
3000	26
4000	30
5000	35

Reciprocating Pumps - Speed Correction vs. Water Temperature

Speed reduction percentage based on water temperature (°C) for reciprocating pumps.

Water Temperature (°C)	Speed Reduction (%)
21	0
27	9
38	18
52	25
66	29
93	34
121	38

Rotary Pumps - Speed Correction vs. Viscosity

Speed reduction percentage based on liquid viscosity (SSU) for rotary pumps.

Liquid Viscosity (SSU)	Speed Reduction (%)
600	2
800	6
1000	10
1500	12
2000	14
4000	20
6000	30
8000	40
10000	50
20000	55
30000	57

Calculator

Inputs

Baseline Speed (RPM)

Speed Reduction (%)

Results

Corrected Speed-- RPM

Positive Displacement Pumps | MEPKit Engineering Tools | MEPKit